Dominant group/Geology

The dominant geology of Orkney, Caithness, and the east of Sutherland is that of Old Red Sandstone. Credit: Richard Webb.

Dominant group appears to be used in geology as a scientific or technical term that has an apparent origin in 1826 (174 b2k). The term itself is an entity within each field. Like a geologist, also a geological entity, so is a dominant group.

In theory, dominant group in geology may have at least four meanings: (1) a dominant group of geology-based entities, (2) geology-based sources, (3) geology-based objects, or (4) a dominant group in some way associated with geology.

Accident hypothesis: dominant group is an accident of whatever processes are operating.

Artifact hypothesis: dominant group may be an artifact of human endeavor or may have preceded humanity.

Association hypothesis: dominant group is associated in some way with the original research.

Bad group hypothesis: dominant group is the group that engages in discrimination, abuse, punishment, and additional criminal activity against other groups. It often has an unfair advantage and uses it to express monopolistic practices.

Control group hypothesis: there is a control group that can be used to study dominant group.

Entity hypothesis: dominant group is an entity within each field where a primary author of original research uses the term.

Evolution hypothesis: dominant group is a product of evolutionary processes, such groups are the evolutionary process, produce evolutionary processes, or are independent of evolutionary processes.

Identifier hypothesis: dominant group is an identifier used by primary source authors of original research to identify an observation in the process of analysis.

Importance hypothesis: dominant group signifies original research results that usually need to be explained by theory and interpretation of experiments.

Indicator hypothesis: dominant group may be an indicator of something as yet not understood by the primary author of original research.

Influence hypothesis: dominant group is included in a primary source article containing original research to indicate influence or an influential phenomenon.

Interest hypothesis: dominant group is a theoretical entity used by scholarly authors of primary sources for phenomena of interest.

Metadefinition hypothesis: all uses of dominant group by all primary source authors of original research are included in the metadefinition for dominant group.

Null hypothesis: there is no significant or special meaning of dominant group in any sentence or figure caption in any refereed journal article.

Object hypothesis: dominant group is an object within each field where a primary author of original research uses the term.

Obvious hypothesis: the only meaning of dominant group is the one found in Mosby's Medical Dictionary.

Original research hypothesis: dominant group is included in a primary source article by the author to indicate that the article contains original research.

Primordial hypothesis: dominant group is a primordial concept inherent to humans such that every language or other form of communication no matter how old or whether extinct, on the verge of extinction, or not, has at least a synonym for dominant group.

Purpose hypothesis: dominant group is written into articles by authors for a purpose.

Regional hypothesis: dominant group, when it occurs, is only a manifestation of the limitations within a region. Variation of those limitations may result in the loss of a dominant group with the eventual appearance of a new one or none at all.

Source hypothesis: dominant group is a source within each field where a primary author of original research uses the term.

Term hypothesis: dominant group is a significant term that may require a 'rigorous definition' or application and verification of an empirical definition.

Examples from primary sources are to be used to prove or disprove each hypothesis. These can be collected per subject or in general.

'Orderable' means that any synonym from within the first category can be ordered with any synonym from the second category to form an alternate term for "dominant group"; for example, "superior class", "influential sect", "master assembly", "most important group", and "dominant painting". "Dominant" falls into category 171. "Group" is in category 61. Further, any word which has its most or much more common usage within these categories may also form an alternate term, such as "ruling group", where "ruling" has its most common usage in category 739, or "dominant party", where "party" is in category 74. "Taxon" or "taxa" are like "species" in category 61. "Society" is in category 786 so there is a dominant society as a relative synonym for a dominant group.

"The Grunehogna Craton (GC, East Antarctica) is interpreted as part of the Archaean Kaapvaal Craton of southern Africa prior to Gondwana breakup. The basement of the GC is exposed only within a small area comprising the dominantly leucocratic Annandagstoppane (ADT) S-type granite."[4]

"The granite is relatively fine grained (1–2 mm dominant grain size) and isotropic without any signs of ductile or brittle deformation."[4]

"The dominant group of zircons with a crystallization age of 3067 ± 8 Ma is interpreted to define the crystallization age of the ADT granite."[4]

"[T]onalite–trondjemite–granodiorite (TTG) [is] in the source region of the zircon-producing magmas."[4]

"The dominant group of TTG gneisses in the [Swaziland Block] SB, however, formed from plutons intruded into the Barberton greenstone belt (BGB) between ∼3·46 and 3·43 Ga (Poujol et al., 2003)."[4]

In the above primary source, "dominant grain size" is used only once and dominant group is used twice by the authors. Additional uses of "dominant": dominant granite-twice, "most dominant component"-once, and "dominant mechanisms"-once.

"Group" is used fifty-two times: eight for stratigraphic units (eg. Ritscherflya Supergroup) and after the above the remaining refer to various age groups of zircons, the focus of the original research.

Below is an effort to evaluate each dominant group hypothesis for the above dominant group uses.

Accident hypothesis: dominant group is an accident of whatever processes are operating.

To test this hypothesis, assume that "dominant grain size" is an observation by the author, regarding the most frequent or largest average grain size, and it is an accident of the authors or the observations.

The synonym uses of dominant group, three out of seven uses of "dominant" suggest its not an accidental use by the authors but a word choice preference.

The natural processes could still be accidental.

Although grain size distributions sometimes approximate a bimodal or multimodal distribution, as in the figure on the right from another author, usually there is one significant peak in the frequency distribution, as suggested in the unprocessed distribution. But this is usually not the largest grain size. Dominance then is most likely related by the above author to the peak frequency of occurrence. The process that made a particular grain size the most frequent may be random (an accident) or a product of the grain production process (not an accident even though it may be best approximated by a random distribution). In the above primary source, the process is most likely magma cooling and grain crystallization from the melt following a fairly complex phase diagram.

For the second set of authors, "Mean grain size, however, reached a steady value irrespective of axial strain. This implies that a limited amount of strain is accommodated on each strand with further strain requiring new strands to form."[5]

"Graph of incremental total volume (%) vs grain diameter (mm) [on the right] is from the laser particle size analysis on a log linear scale. The plot compares the grain-size distributions of gouge strands sampled from tests carried out at increasing amounts of axial strain (4.2, 6.5 and 11.2%). The grain-size distribution for undeformed Locharbriggs sandstone is plotted for comparison. The three gouge samples have very similar characteristic curves which exhibit both the same peak value, indicating significant grain-size reduction with respect to the undeformed sample, and a similar range of grain sizes."[5]

The figure on the right clearly shows that the changes in the grain size distribution were caused by the axial strain, not an accident. The authors of the second primary source did not use the term dominant group.

This aerial view shows a portion of the San Andreas fault in California. Credit: Robert E. Wallace, USGS USA.

Def. the intellectual and practical activity encompassing the systematic study through observation and experiment of the Earth's physical structure and substance, its history and origin, and the processes that act on it, especially by examination of its rocks, is called geology.

Def. the intellectual and practical activity encompassing the systematic study through observation and experiment of naturally occurring astronomical rocky objects, their physical structure and substance, history and origin, and the processes that act on them, especially by examination of their rocks, is called astrogeology.

This portrait of Victor Goldschmidt (father of geochemistry) dates from around 1905. Credit: Yellowmellow45.

"Those who do not share the values of the dominant group may have been separated out, voluntarily or otherwise."[6]

"Because most of the lectures in the eighteenth century and even some in the beginning of the nineteenth were delivered in Latin, ex-seminarians and priests' sons had a decided advantage over other students and formed the dominant group in the first student bodies."[7]

"The spatial and temporal variations observed in these magmas, which comprise a dominant group of potassic lavas derived from the enriched lithospheric mantle and collision-type adakites produced by partial melting of thickened mafic lower crust in the Lhasa terrane, imply the thermal structure of Tibetan deep lithosphere to have also evolved."[8]

"In these islands a basaltic succession, originally estimated by James Geikie and Georgey as no less than 14,000 feet in thickness, contains a dominant group of lavas, non-porphyritic and porphyritic, which betray in their petrography and chemistry a distinct tholeiitic character."[9]

Main sorption processes of adsorbate molecules and atoms at mineral-water interface are used to remediate contaminated sites and clean wastewaters. Credit: Alain Manceau.

"The South Platte pegmatite district is well known for its significant enrichment in the rare earth elements (REE)".[16]

"The replacement phases of the district can be subdivided into two well-defined assemblages, with allanite representing the LREE-dominant group and samarskite representing the HREE-dominant group."[16]

"Overall, polyunsaturated fatty acids were the dominant group of fatty acids (Table 2), except at Station 6 where saturated fatty acids also dominated the fatty acid pool."[18]

"Composite tetrafunctionalised biohopanoids were the dominant group of bacteriohopanepolyols in all other sediments, and are likely to be a major source of the geologically occurring extended hopanes."[19]

Two geochronologists and one Paleontologist collect ash at the Cretaceous-Paleogene Boundary in Wyoming, USA. Credit: Dcondon.

"A date of 2809 ± 5 Ma was determined from 25 concordant analyses of 10 grains of the dominant group, and a 2945 ± 7 Ma date from 7 other grains."[20]

"The relative probability plot (Fig. 10) shows a dominant group of 207 Pb/ 206 Pb ages at ~1560 Ma with minor scattered analyses around 1500 Ma and younger and one slightly older analysis at about 1630 Ma."[21]

"Analyses from the dominant group and those that are consistent to within each of their analytical errors produced a weighted mean age of 550 ± 3 Ma (MSWD = 1.3, n = 11; Fig. 8C)."[22]

Def. "the measurement and representation of Earth, its gravitational field and geodynamic phenomena (polar motion, Earth tides, and crustal motion) in three‐dimensional, time‐varying space"[23] is called geodesy.

"This is expected since they are successive harmonics of the M2 dominant group."[24]

"Consequently, the resulting age is an average on all sources, which is often close to the dominant group, when one age population is volumetrically dominant."[25]

"The oldest and north at varying angles, so that the oldest sediments most dominant group (RG-1) contains faults that strike within the grabens have the steepest northward dip, with 75–110° and is the group that includes most of the faults"[26]

Moorong Geodetic Station put in place by the Central Mapping Authority located on top of Mount Moorong in the Pomingalarna Reserve. Credit: Bidgee.

Def. "the measurement and representation of the earth, its gravitational field and geodynamic phenomena (polar motion, earth tides, and tectonic motion) in three-dimensional, time-varying space"[27] is called geodetics.

"Concerning equilibrium networks it turns out that as in GJ (2003), equilibrium networks have a dominant group architecture, ie a group of firms are linked to each other while other firms have no links at all."[28]

"The dominant group of deposits is fine sands accounting for 41.3% of the population (44 samples)."[29]

"Third, an interest in legal geography, regarding maps as means to legitimize ownership claims by the dominant group to indigenous lands, and as sources that may be used in present land ownership disputes. Here we focus mainly on the first approach."[30]

Def. each continuous surface of a landscape that is observable in its entirety and has consistence of form or regular change of form is called a landform.

Def. an assemblage of surfaces that are a portion of land, region, or territory, observable in its entirety is called a landscape.

"It was the dominant group on sediment-covered reefs below 75 m depth."[32]

"Because they are isolated from influxes originating from overland transport of nutrients and sediments, they have little opportunity to influence the quality of ground water and surface water; hence, their interactions with the atmosphere through acid deposition and carbon dioxide exchanges become a dominant group of functions as described above."[33]

"A tributary classification was defined by dominant group membership (including first and second order streams Milksick Branch, Auger Fork, Frozen Creek and Cobb Creek; Table 1)."[34]

"The algae was the dominant group, and all obtained sequences belonged to Chlamydomonadales."[37]

"Bacteria of β-Proteobacteria were dominant group in Nam Co, accounting for 61% of the total amount."[38]

"Phototrophs were found to be the dominant group in terms of productivity and biomass in previous analyses (Mueller et al., 2005) and we therefore focused on cyanobacteria, green algae, diatoms, and other protists."[39]

"Historical geology is a study of life forms represented in the fossil record, as well as the chronology of geologic processes. Of the three main rock groups (igneous, metamorphic and sedimentary), sedimentary rocks are clearly the dominant group in Florida geology."[40]

"The beginning of the Cenozoic saw the establishment of mammals as the dominant group of large-bodied terrestrial vertebrates."[41]

"Such preemption might take a long time, as the realized speciation rate of the dominant group would be lowered owing to the presence of the other groups in the adaptive space, and as in many groups average species durations are several million years."[42]

"Waters of “local” rainfall and imported, “Colorado” River aqueduct origins are easily distinguished from dominant, “native” Santa Ana river compositions by use of hydrogen and oxygen stable isotope analysis."[44]

"The Santa Ana river isotopic signature will also be shown to be nearly identical to that observed for the dominant group of Orange County groundwater wells sampled in this study".[44]

"Phenols form a dominant group of compounds deposited at the site but their abundance in the groundwater is reduced by an order of magnitude within 50 m of the lagoon."[45]

This shows sharp and lustrous, chocolate-colored eudialyte crystals associated with black aegirine from very close to the Type Locality in Greenland. Credit: Rob Lavinsky.

"We take the boundary between the lithium and calcium, and lithium and magnesium–iron–manganese amphiboles at Li: Ca and Li: (Mg + Fe + Mn) ratios of 0.50 (ie, we use the criterion of the dominant cation or, in the case of the magnesium–iron–manganese amphiboles, the dominant group of cations) in both SCHEME 1 and SCHEME 2."[46]

"The main concem in the Ba-dominant group is substitution at the T site; for walthierite, such substitution was not detected (Li et al. 1992)."[47]

"For the Al-dominant group (Fig. 5), goyazite and svanbergite have long been used to indicate the PO4 and PO4-SO4 minerals, respectively."[47]

"Oceanography..., also called oceanology or marine science, ... studies the ocean. It covers a wide range of topics, including marine organisms and ecosystem dynamics; ocean currents, waves, and geophysical fluid dynamics; plate tectonics and the geology of the sea floor; and fluxes of various chemical substances and physical properties within the ocean and across its boundaries."[48]

"Towards the middle of isotope stage 1, there is a pronounced decrease in transparent shells, while the opaque-white ones become the dominant group."[49]

A rhyolite boulder near Carn Alw shows the characteristic pattern of swirling or parallel layers called flow banding caused by the molten magma meeting a hard surface before cooling and setting. Credit: ceridwen.

With respect to the igneous petrology of the southern Paraná of southern Brazil, "[i]t was well known from surface mapping that LPT rocks were the dominant group in the southern Parana, but the borehole data indicate that LPT rocks underlie HPT, and that they in turn are overlain by IPT rocks."[53] The basalts of the Parana continental flood basalt (CFB) province may be subdivided into two groups on the basis of their titanium (Ti) and phosphorus (P) contents: the high P and high Ti group (HPT) have TiO2 > 3 % and P2O5 > 0.4 % and the low P and low Ti group (LPT) have TiO2 < 2 % and P2O5 < 0.3 %.[53] More recent work suggests there is a significant intermediate P and intermediate Ti group (IPT).[53]

"The dominant magma type appears to have evolved from LPT to HPT to IPT with time, and the site of the magmatism may also have migrated northwards.".[53] While the borehole and road cut evidence does not appear to effect the dominant LPT group in the south, it suggests that the IPT group may be dominant in the north, with the HPT group being dominant between these two.[53]

"The granite is relatively fine grained (1–2 mm dominant grain size) and isotropic without any signs of ductile or brittle deformation."[4]

Notation: let the symbol ADT stand for Annandagstoppane, and Ma stand for million years ago.

"The dominant group of zircons with a crystallization age of 3067 ± 8 Ma is interpreted to define the crystallization age of the ADT granite."[4]

Maw sit sit is a very rare, complex, polymineralic metamorphic rock. Credit: James St. John.

On the serpentinization processes in ultramafic rocks from the Mid-Atlantic Ridge south of the Kane Fracture Zone, latitude 23° N, at Site 670, "[o]range to pale-green serpentinized harzburgites with a well-defined spinel and orthopyroxene foliation are the volumetrically dominant group of samples (Shipboard Scientific Party, 1988)."[54]

"[S]erpentinization in our sample set occurred at temperatures greater than 350°C."[54] "In our set of serpentinized ultramafic rocks, the oxygen-isotope results also indicate that serpentinization occurred at high (between 0.3 and 1.25), but presumably variable, water:rock ratios, assuming that the serpentinizing fluid was seawater or 18O-enriched seawater."[54]

This image shows the sedimentary rock layers at Zabriskie Point in Death Valley, USA. Credit: Brigitte Werner (werner22brigitte).

In the Lower Cretaceoussediments of south-eastern Alexander Island are a "palaeogeographical distribution of conglomerate beds".[55] From the petrology of the pebbles for seven conglomerate horizons, the pebbles can be divided into four compositional groups whose proportional representations are determined.[55] With respect to the first compositional group of pebbles of volcanic material, "[i]ncluded in this dominant group are a wide range of volcanic rocks, both lavas and tuffs."[55]

Further, three of the seven conglomerate horizons have a local majority of pebbles of volcanic material, while the other four have a majority of pebbles of plutonic material.[55] The other two compositional groups are 'hypabyssal' and 'metasedimentary'.[55]

The "whole change elapsed just opposite the course of events that characterized the great glacial oscillations with sudden warming followed by slow cooling. Therefore, the two phenomena hardly have the same cause."[57]

"Our data strengthen this hypothesis and show unequivocally that haplogroup C, an endemic and dominant group of North American mammoths, was basal to all remaining Asian mammoth populations (including that on Wrangel Island)."[58]

"Within the present study, however, the Tanytarsini have not been subdivided. This is clearly a dominant group at certain times."[59]

"Ahl al Oughlam lacks the diversity of murids found in East African sites of this age, but also fully lacks any arvicolid, the dominant group in Europe at that time."[60]

"Where multiple grain single aliquot OSL measurements provide a range of dose values, the dating specialist may choose to accept a dominant group of aliquots and reject outliers."[61]

"Each factor is described according to the dominant group of variables."[67]

"The conglomerates are divided markedly into a dominant group, which is light colored with little evidence of humic material, and a subordinate group in which the matrix is dark with humic matter."[68]

"The relationship between the sandstone petrography and seismic stratigraphy is shown in Figure 9. Group 1 is the dominant group and consists of very fine- to medium-grained sandstones with relatively good sorting."[69]

"The second and dominant group is yellow reddish granite soil which is coarse and highly dispersible."[73]

"The sediments were dominantly consisted of silt and clay of percentage over 95%, and that the <30 μm particle group was the “dominant group”."[74]

"Hydrophobic acids, which constitute the dominant group of dissolved organic compounds in the humic layer, are effectively retained as water percolates through E and B horizons of podzol profiles (East- house et al., 1992)."[75]

"The numerically dominant group throughout zones A and B is the benthic Fragilaria".[76]

"The dominant group consists of normal faults nearly parallel to the arc."[77]

"Unfortunately, so far, Eocene beds have not been adequately studied biostratigraphycally, despite the fact that they have a very abundant microfauna with the predominant group of nummulitines in all levels."[78]

"The trimaceritic coal facies: In this facies, vitrinite, liptinite and inertinite are all well represented. Vitrinite, however, is still the dominant group".[79]

"The granitoid layers include a dominant group of equigranular, coarse- to medium-grained, massive to weakly foliated gneisses that range in composition from granite to granodiorite to quartz".[80]

"As the diagram (Fig.10) shows, the majority of the steepest slopes is dipping both to the northwest and to the southeast, belonging to the dominant group of ridges striking NE-SW".[84]

"The dominant group consists of normal faults nearly parallel to the arc."[85]

"The basalts most enriched in incompatible elements (Group 1) are spatially restricted to the central part of the axial volcano, whereas the least enriched basalts (Group 3, the dominant group of basalts) are distributed along the entire segment."[86]

"The first and dominant group contains plagioclase, clinopyroxene, actinolite, chlorite, epidote as the essential minerals and calcite, opaques and quartz as accessories."[87]